1. Field of the Invention
This invention relates to a compact zoom lens system for so-called still cameras, which zoom ratio is about three times from the wide angle to the sub-long focal length.
2. Description of the Prior Art
Recently, zoom lens systems which are wide magnification variable and compact and have a high performance, are in high demand, for use with still cameras.
With this, new type zoom lens systems have been groped in an attempt to break the limitation encountered in so-called mechanically-corrected or optically-corrected type zoom lens systems heretofore developed. In the past, several types of zoom lens systems have been proposed as wide magnification-variable zoom lens systems of the type as described, one of which is a zoom lens system composed of three lens groups having a refractive power arrangement of positive, negative and positive. This lens system has a barrel which is relatively simple in construction, but if an attempt is made to increase the ratio of magnification while the system remains to be compact, the refractive power of each lens group must be intensified, resulting in a difficulty in correcting aberration.